Insulated electrical terminal



Aug. 13, 1940. J. a. JOHANSON I iNSULATED ELECTRICAL TERMINAL Filed Feb. 21., 1938 Patented Aug. 13, 1940 v UNITED STATES PATENT OFFICE.

INSULATED ELECTRICAL TERMINAL John E. Johanson, Boonton, N. J., assignor to Aircraft Radio Corporation, Boonton, N. J., a corporation of New Jersey Application February 21, 1938, Serial No. 191,813

2 Claims. (Cl. 174-60) This invention relates to insulated electrical an insulated terminal assembly of the plug type; terminals and particularly to insulated electrical and terminals for use in radio transmitters and Fig. 11 is a fragmentary perspective view of an receivers. insulated terminal construction for small resistor It is frequently desirable to enclose various units.

electrical units in tightly sealed metal cans to pro- In the drawing, the reference numeral l identect the units from the moisture of the air, and tifies the outer stem of a tubular terminal member the methods previously employed have not been having an enlarged base section 2 and a relaentirely satisfactory in the case of small units, tively thin-walled inner sleeve 3. The inner ansuch as by-pass condensers, that are to be used nular face 2a of the base is undercut or "raked" in at high frequencies. at a small angle to insure a clamping action at Objects of this invention are to provide insuthe periphery of the base section when the sleeve lated electrical terminals, having good electrical 3 is passed through an opening in 'an insulating characteristics when used at radio frequencies. disk 4 and spun or expanded upon a washer 5 Objects are to provide insulated terminals in to secure the terminal member to the disk. which the terminal or terminal members extend The insulatingdisk 4 is preferably an assemthrough and a e C ed y a d sk o nsu a bly of punched sheets of mica when the terminal ma er t e s being Se ed W hi a ring is to be used on parts of radio equipment and/or having a flange that is r d, soldered Otherwhen the terminal assembly is to be air tight. so wise attached to the housing or panel of the radio The outer edge of the insulating disk 4 is seated '20 dev ee p i y, Objects are to provide on an internal shoulder of a mounting sleeve 6 hermetically sealed housings for electrical units, and is Secured t i by Spinning t larger the units having electrical terminals that exdiameter end e f the Sleeve down upon t tend through the housing and are insulated theremetal Washer 1 that rests upon the disk 4 The from. Objects are to provide Se electrical smaller diameter end 6b of the sleeve is to be 25 umts of the type stated in which the insulated spun outwardly, as shown in dotted lines in Fig. terminals are tubular members through which the 2).) secure the mounting Sleeve and terminal leads of the unit extend, the tubular members assembly to the panel or casing being deformed mechanically to Seal their bores The insulated terminal constructionof Fig. 2 and then soldered to the leads at and across their is particularly adapted for use with electrical 6 outer ends to insure good electrical contacts and units that are hermetically Sealed in metal tight Sealing of the housingings. Mica is brittle but is protected against These and other objects and advantages of the damage during the Spinning Operation by the invention Wm be apparent from the following metal washer I and the coefiicient of expansion f i i s? taken with the acwmpanymg of mica is such that the tight connections to the 35 raw ng in w c Fig. 1 is an enlarged central section through a gg g gg ;;:f gz gg g gg gfig g g ggi fiigg g section through extent shown in solid lines in Fig. 2, may be impregnated with wax to preclude any leakage of an ins-mated termma'l assembly embodying the air through the mica disk 4 when the terminal 40 invention, the assembly being shown in position i to be d 1 d t for mounting on a panel or casing; 5 use on a Sea e con amer' Figs 3 to 5 inclusive, are central setions The successive steps in the connection of a lead illustrating successive steps in the connection of to the insulated terminal stem are Shown m a lead to the terminal assembly; Figs. 3 to 5. The lead 9 is passed through the 6 is a central section through a modified bore of the terminal member, and the stem I is form f a hollow terminal member; then crimped or rolled to force a section lw into Fig. 7 is a similar section showing the terminal tight engagement with the lead The member mechanically sealed upon a lead; end of the lead 9 is cut off and solder I0 is ap- Fig. 8 is an enlarged side elevation, with parts plied to the Outer ends of the Stem and lead 3 so in section, of a shielded condenser assembly, the to make a good elecmcal connection and t0 form terminals being of t t shown in pi 6 a further seal for the bore of the terminal. d 7; v As shown in Figs. 6 and "l, the outer end lb 'Flg'. 9is a plan view of the same; of the terminal member I' may be enlarged Fig. lO'is a side elevation, partly in section, of to provide ample metal for the mechanical seal 55 and a flat surface of appreciable size to receive solder l.

An application of the invention to a sealed condenser assembly is shown in Figs. 8 and 9. The mounting rings 6 of the several terminals are riveted into openings in the upper wall of the shield can I I, and solder I2 is applied at the edges 01 the rings 6 to form tight joints with the shield can. The condensers [-3 are placed in the can in the usual manner, and the condenser leads are passed through the bores of the terminal members. Wax may be filled into the can II before the bottom I4 is soldered to the can.

The terminals are next mechanically sealed upon and then soldered to the respective leads 9.

(The electrical unit or condenser block can be connected into a radio circuit in the usual manner. The casing has integral lugs l5 for securing the unit to a chassis, and the leads l6 to the external circuit are twisted upon and soldered to the terminal stems. It is particularly to be noted that the soldering operations do not present any difliculties as the bores of the'terminal members are sealed mechanically upon the leads 9. The

pressure within the sealed can will difier mate-' rially from atmospheric during the soldering operations but the mechanical seal prevents the molten. solder from flowing into the casing in the case of a reduced pressure within the casing.

Other types of terminal members may be secured to the insulating disk when pin or socket connections are desired. The assembly illustrated in Fig. 10 includes a plurality of flexible pin terminals l'l whose lower ends pass through mica disk I8 and are riveted over upon the soldering lugs IS. The mica sheets of the disk It are secured in a ring 6' by spinning the end of the ring sleeve down upon the metal washer l which protects the mica during the spinning operation. The assembly is secured within an opening in a panel 8' in the manner described above with reference to Fig. 2.

The form of the invention shown in Fig. 11 provides a compact terminal block assembly for connecting a number of small resistor units into a radio circuit. Terminal assemblies such as shown in Fig. 2, but with soldering lugs 5' (in place of the washers 5 of Fig. 2, are mounted in pairs on a sheet 20 of mica or other insulating material, thespacing of the terminals of each preferably, by bolting the insulating strip 20 pair being somewhat greater than the length of the resistor units 2|. The pig-tail leads 22 of the resistors are bent over at right angles, inserted in the bores of the terminal stems I, and secured by applying solder 23. Circuit connections to the resistors are made at the soldering lugs v5', and the resistor assembly may be supported mechanically by those connections otr, 0 the chassis of the radio apparatus.

The embodiments herein described are typical of the invention and it is to be understood that other variations which may occur to those skilled in the art fall within the spirit of my invention as set forth in the following claims.

I claim:

1. In a hermetically sealed assembly of the type including an electrical unit within a closed metal casing, a tubular metal terminal having an inner end opening into the closed metal casing, means sealing the inner end of the tubular memher to .and insulating the same from thecasing and a lead for the electrical unit extending through said tubular member; the combination with said tubular member of means blocking the flow of air to and from the casing through said tubular member, said blocking means comprising metal of the tubular member deformed mechanically into sealing engagement with said lead and solder uniting the lead and tubular member at a point more distant from the casing than the deformed metal of the tubular member.

2. In a hermetically sealed assembly of the type including an electrical unit withina closed metal casing, a tubular metal terminal having an inner end opening into the closed metal casing, means sealing the inner end of the tubular member to and insulating the same from the casing and a lead for the electrical unit extending through said tubular member; the combination with said tubular member of-means blocking the flow of air to and from the casing through said tubular member, said blocking means comprising solder uniting the outer ends of the tubular member and the lead and metal of. an intermediate portion of the tubular member mechanifalliy deformed into sealing engagement with said JOHN E. YJOHANSON. 

